[
  {
    "tenant": "customer-a",
    "meter": "completed_pages",
    "id": "u1",
    "kind": "usage",
    "period": "2026-05",
    "units": 100
  },
  {
    "tenant": "customer-a",
    "meter": "completed_pages",
    "id": "u1",
    "kind": "usage",
    "period": "2026-05",
    "units": 100
  },
  {
    "tenant": "customer-a",
    "meter": "completed_pages",
    "id": "u2",
    "kind": "usage",
    "period": "2026-06",
    "units": 40
  },
  {
    "tenant": "customer-a",
    "meter": "completed_pages",
    "id": "c1",
    "kind": "correction",
    "ref": "u1",
    "units": -20
  },
  {
    "tenant": "customer-a",
    "meter": "completed_pages",
    "id": "u3",
    "kind": "usage",
    "period": "2026-05",
    "units": 30
  },
  {
    "tenant": "customer-a",
    "meter": "completed_pages",
    "id": "c1",
    "kind": "correction",
    "ref": "u1",
    "units": -20
  }
]